In the generations since Bob Dylan melded the lyrical prowess of folk with rock sensibilities, music fans seem to have forgotten, or at least largely ignored, the fact that songs can be both rich literature and great tunes. And that bare and bitter emotion can be wonderfully entertaining.

Jason Isbell, the former guitarist/vocalist/songwriter for alt-country/Southern rockers Drive By Truckers, was a resounding reminder of that with his concert Thursday at Keswick Theatre in Glenside.

Nearly every tune in his 19-song, nearly two-hour show was devastatingly good: Life lessons that were buoyant or bitter, and sometimes both. Some were quiet, others rocking.

On every one, Isbell sounded wholly invested – his voice by turns brooding, soaring and blasting. And his four-man band was equally impassioned.

It helped that the material was uniformly great, from the opening “Stockholm,” full of chime-y Americana rock and heartfelt lyrics that tell of being not-altogether-comfortably anchored by love -- an honestly conflicted emotion rare in songs these days.

BRIAN HINELINE/Special to The Morning Call

Jason Isbell at Keswick Theatre in Glenside

Jason Isbell at Keswick Theatre in Glenside (BRIAN HINELINE/Special to The Morning Call)

That song was among 10 Isbell did from his most recent, near-masterpiece album “Southeastern.” And as good as all the songs were, the ones from the new album – which chronicles his road to sobriety --were among the best.

A strong example was “Live Oak,” a raw confessional about struggling with the legacy – both good and bad – of his former self. Isbell started it alone and a cappella, in a clear, strong voice, before the band kicked in.

One of the best was “Different Days,” another look at his former self, and even more stunningly confessional. “My daddy told me, I believe he told me true,” Isbell sang. “That the right thing’s always the hardest thing to do,”

BRIAN HINELINE/Special to The Morning Call

Jason Isbell at Keswick Theatre in Glenside

Jason Isbell at Keswick Theatre in Glenside (BRIAN HINELINE/Special to The Morning Call)

Before that song, Isbell switched from electric guitar to acoustic – which he identified as a C.F. Martin model he had gotten at the Nazareth guitar maker’s factory that day. (He told the crowd the area was fortunate to have Martin nearby).

“Relatively Easy” was a country shuffle that grew on you as it went, so that by the end of the song you were won over. He sang two new songs of deep tragedy -- “Songs That She Sang in the Shower” and “Elephant” -- as dark, slow burns.

But perhaps the best of all was “Cover Me Up,” which Isbell said he wrote and plays for his wife. It, too, started with him alone on the Martin in a spotlight, his voice soaring and blasting passionately, the line “I sobered up/And I swore that stuff forever this time” bringing cheers.

At the song’s end, the nearly sold-out audience – which was enthusiastically supportive all night – gave Isbell a standing ovation.

It wasn’t only Isbell’s singing that was great. On the new “Flying Over Water,” he played a blazing guitar solo that was as forceful as his vocals. The slow-and-intense modern-day western “Decoration Day” – the title track from the 2003 album that was his first with Drive By Truckers – also saw him play a searing guitar solo.

In all, he played four Drive By Truckers songs, starting with the slower but no less rocking “Goddamn Lonely Love,” with another guitar solo.

Other songs from his years in between with his band 400 Unit were very good, too. The country shuffle “Tour of Duty” bared just as much emotion: “I've done my tour of duty,” he sings to the woman he’s addressing in the song, “and now I'm going to put you in the family way.”

And “Codeine” – just him and the Martin backed by accordion – was wonderful in the way its warm and jaunty music was betrayed by the dark lyrics.

Isbell closed the main part of the set by proving he can rock equally as well, on the flat-out dirty groove of “Go It Alone,” then Drive By Truckers’ “Outfit,” on which he played another solo.

His encore opened with Drive By Truckers’ “Danko/Manuel,” a tribute to members of The Band – an obvious influence -- that showed his work with his old band could be brooding and dark, as well. Then he played the new disc’s most rocking cut, a swinging, rollicking “Super 8” that was another of the night’s best.

The night closed with a burning, seven-minute version of The Rolling Stones’ “Can’t You Hear Me Knocking,” Isbell’s voice hollering out before he closed with a two-minute guitar solo.

It was as if, after a night of such thoughtful music, Isbell decided to show the audience he could rock, as well. If the public in general has forgotten how good music can be, he wasn’t going to let them forget a night like this.